Lighting

Candela to Lumens Calculation — ChiefEngineer.in

Worked step-by-step example. Convert luminous intensity to luminous flux for a specified beam angle. Open interactive calculator →

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Result

Flux
314.16 lm

Formula

Φv = Iv × Ω
Ω = 2π(1 − cos θ), θ = half-angle

Variables

  • Iv — luminous intensity (cd)
  • Ω — solid angle (sr)
  • θ — beam half-angle

Worked Example

Input: I = 100 cd, full beam angle = 120°

Result: Φ ≈ 314.16 lm

Assumptions & Notes

Assumes uniform intensity across the beam. Real lamps have non-uniform distributions.